Britain's Sarah Stevenson was at the centre of an extraordinary controversy in the taekwondo competition when officials reversed the result of her second round heavyweight bout against the double Olympic champion from China, Chen Zhong, and awarded the fight to the British fighter. Stevenson went on to take on to take a bronze medal, becoming Britain's first-ever medallist in Olympic taekwondo.

The controversy erupted when a kick from Stevenson to the face of Chen, in the dying seconds of their fight, was not registered. At that stage, Chen was leading by a single point, but was not fighting like a double Olympic champion. The kick from Stevenson, which split the Chinese fighter's lip, would have been worth two points, and given the Doncaster fighter the match.

In taekwondo, points are awarded when three of the fours judges, who sit at the corners of the mat, agree that a score has been made. But only two of the four judges recorded the hit, despite Stevenson's protests. "I believe I should have won it, there's no way that she was better than me," said Stevenson, who had also contested earlier decisions by the judges.

Television replays after the fight showed clearly that Stevenson's foot had made full contact with Chen's face, and the performance director of the British team, Gary Hall, immediately filed a protest. It was apparent, when Chen came out on to the mat at the scheduled time for her semi-final and then left the arena that something was amiss.

About 15 minutes later, the technical director Rene Bundelli announced that the result of the fight had been overturned and Stevenson would fight the semi-final. It was a decision that shocked the primarily Chinese audience for Chen has won both Olympic heavyweight (+67kg) titles, since the sport became Olympic in 2000.

"It was an unprecedented decision. The standard procedure is to say 'I'm sorry we are wrong but now can we get on'. But it had to be the correct decision and it's a credit to the organisers and the Chinese team who endorsed it," said Hall.

Stevenson is the most experienced member of the three-strong British taekwondo team, having contested the last two Olympics. In Sydney, when just 17, the Doncaster fighter finished fourth in the under 67kg class. She went up a weight for Athens and, as European champion, was strongly fancied for a medal then, but in the first round was beaten in a high-scoring fight by the Italian Adriana Carmona, the referee awarding the Italian the fight with the scores tied at eight-all.

Returning to the mat for the semi-final against Espinoza, Stevenson looked a shadow of the fighter who had matched and, at times, outfought Chen. The Mexican's counter blows quickly brought up two scores in the opening round and, by the end of the second round, she had established a 4-1 lead. It all looked irretrievable, and Stevenson, who was limping badly, was unable to reduce the deficit in the final round.

"My mind and body wasn't ready. I have beaten that girl twice. I thought my next fight was in the repechage and I was focused on that. That (the reinstatement) just messed my whole game up in terms of tactics. We had 20 minutes of looking at videos and going though mental strategies - my mind wasn't focused," said Stevenson.

It was a reinvigorated Stevenson who returned to the mat to face theEgyptian Noha Abd Rabo in one of the two bronze medals fights. Taekwondo, like boxing and judo, awards two bronze medals for every weight. The 25-year-old was fast and precise and, although she had one point deducted for an illegal move, she was a comfortable 5-1 winner to become Britain's 46th medallist of these Games.